J/A+A/463/671 Rotational velocities of A-type stars. III. (Royer+, 2007)
Rotational velocities of A-type stars. III. Velocity distributions.
Royer F., Zorec J., Gomez A.E.
<Astron. Astrophys. 463, 671 (2007)>
=2007A&A...463..671R 2007A&A...463..671R
ADC_Keywords: Stars, A-type ; Rotational velocities
Keywords: stars: early-type - stars: rotation
Abstract:
A sample of vsini of B9 to F2-type main sequence single stars has been
built from highly homogeneous vsini parameters determined for a large
sample cleansed of objects presenting the Am and Ap phenomenon as well
as of all known binaries. The aim is to study the distributions of
rotational velocities in the mass range of A-type stars for normal
single objects.
Robust statistical methods are used to rectify the vsini distributions
for the projection effect and the error distribution. The equatorial
velocity distributions are obtained for about 1100 stars divided in
six groups defined by the spectral type, under the assumption of
randomly orientated rotational axes.
We show that late B and early A-type main-sequence stars have genuine
bimodal distributions of true equatorial rotational velocities
probably due to angular momentum loss and redistribution that the star
underwent before reaching the main sequence. A striking lack of slow
rotators is noticed among intermediate and late A-type stars.
Description:
The total sample of stellar rotational velocities is presented. The
1541 stars are listed with their projected rotational velocity value
(vsini), their spectral type, the subgroup in which they are
classified according to their spectral type, and whether or not they
are known to a chemically peculiar object (CP) and/or a close binary
object (CB).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 35 1541 List of the 1541 B9- to F2-type stars, with their
vsini value, spectral type, associated subgroup
and classification
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See also:
III/22 : Rotation of Evolving A and F Stars (Danziger+ 1972)
III/226 : Rotational Velocities of Stars (Glebocki+ 2000)
J/A+AS/118/545 : Rotational velocities of F dwarfs (Groot+, 1996)
J/ApJ/573/359 : Rotational velocities of B stars from BSC (Abt+, 2002)
J/A+A/398/647 : Rotational velocities of F and G stars (Reiners+, 2003)
J/A+A/381/105 : Rotational velocities of A-type stars. I. (Royer+, 2002)
J/A+A/393/897 : Rotational velocities of A-type stars II. (Royer+, 2002)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD number
8- 10 I3 km/s vsini Projected rotational velocity
12- 22 A11 --- SpType MK spectral type
25- 29 A5 --- Subgroup Subgroup in spectral type
31- 35 A5 --- Class Classification (1)
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Note (1): Classification as follows:
CP = Chemically peculiar star
CB = Close binary star
blank = "normal" star
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Acknowledgements:
Frederic Royer, frederic.royer(at)obspm(fr)
(End) F. Royer [Obs. de Paris, France], P. Vannier [CDS] 24-Nov-2006